Recently, the FLJ25416 gene (NCBI GenBank Access No. NM—145018), encoding the hypothetical protein FLJ25416, was known to be associated with cancer (Korean Patent Laid-Open Publication No. 10-2009-0060183).
RNA interference (RNAi) is a process which regulates the expression of genes of interest at a post-transcriptional level as siRNA specifically binds to mRNA transcripts and induces their degradation. Recently, RNAi has become prominent as a solution to problems with the development of conventional chemically synthesized medicines. Able to selectively regulate the expression of proteins of interest at a post-transcriptional level, RNAi is utilized in the development of therapeutics for various diseases, particularly, tumors. Generally, small molecule chemical drugs optimized for targeting proteins of interest are not developed without a long period of time and a great deal of expense. In contrast, siRNA medicines based on RNAi allows the rapid development of leading compounds optimized for all protein targets including non-druggable targets, which is one of the greatest advantages of the siRNA medicines. Whereas it difficulty is put into the production of protein or antibody drugs because of their complicated processes, siRNA is relatively easy to produce on a mass scale thanks to the easiness of its synthesis and isolation. Further, small nucleic acid molecules such as siRNA have an advantage over protein drugs because such nucleic acids are more stable. In addition, in contrast to conventional drugs, small RNA molecules such as siRNA perform only antagonistic actions on specific target molecules.
The first consideration of therapy with small nucleic acid molecules, such as siRNA, is to select an optimal sequence associated with activity from among the target base sequence. Certain binding sites of target transcripts are known to have the greatest influence on the efficiency of RNAi. A database accumulated over the last few years provides algorithms that allow the design of the sequences of siRNA that regulate the expression of target mRNA. In practice, however, all of the siRNAs constructed by the computational In-Silico design cannot effectively regulate the expression of target RNA within cells or in vivo. Even though the siRNA satisfies the requirement of the complimentary binding with target transcripts, it is known that there are various and still unidentified factors that are involved in determining the efficacy of RNAi, including stability between ribonucleic acids and proteins, intracellular location of ribonucleic acids, the state of the proteins implicated in RNAi, etc. There is therefore a need for a technique by which a candidate group consisting of various target sequences on one gene transcript is set and the optimal member of the candidate group that is the most suitable for use in the interference is selected.